OBJECTIVES: Fetal ultrasound measurements are made in axial, lateral and oblique directions. Lateral resolution is influenced by the beam width of the ultrasound system. To improve lateral resolution and image quality, the beam width has been made narrower; consequently, measurements in the lateral direction are affected and apparently made shorter, approaching the true length. The aims of this study were to explore our database to reveal time-dependent shortening of ultrasound measurements made in the lateral direction, and to assess the extent of beam-width changes by comparing beam-width measurements made on old and new ultrasound machines. METHODS: A total of 41,941 femur length measurements, collected during the time-period 1987-2005, were analyzed, with time as a covariate. Using three ultrasound machines from the 1990s and three newer machines from 2007, we performed 25 series of blinded beam-width measurements on a tissue-mimicking phantom, measuring at depths of 3-8 cm with a 5-MHz transducer. RESULTS: Regression analysis showed time to be a significant covariate. At the same gestational age, femur length measurement was 1.15 (95% CI, 1.08-1.23) mm shorter in the time-period 1999-2005 than in the time-period 1987-1992. Overall, the beam width was 1.08 (95% CI, 0.50-1.65) mm narrower with the new machines than with the old machines. CONCLUSIONS: Technical improvements in modern ultrasound machines that have reduced the beam width affect fetal measurements in the lateral direction. This has clinical implications and new measurement charts are needed.
OBJECTIVES: Fetal ultrasound measurements are made in axial, lateral and oblique directions. Lateral resolution is influenced by the beam width of the ultrasound system. To improve lateral resolution and image quality, the beam width has been made narrower; consequently, measurements in the lateral direction are affected and apparently made shorter, approaching the true length. The aims of this study were to explore our database to reveal time-dependent shortening of ultrasound measurements made in the lateral direction, and to assess the extent of beam-width changes by comparing beam-width measurements made on old and new ultrasound machines. METHODS: A total of 41,941 femur length measurements, collected during the time-period 1987-2005, were analyzed, with time as a covariate. Using three ultrasound machines from the 1990s and three newer machines from 2007, we performed 25 series of blinded beam-width measurements on a tissue-mimicking phantom, measuring at depths of 3-8 cm with a 5-MHz transducer. RESULTS: Regression analysis showed time to be a significant covariate. At the same gestational age, femur length measurement was 1.15 (95% CI, 1.08-1.23) mm shorter in the time-period 1999-2005 than in the time-period 1987-1992. Overall, the beam width was 1.08 (95% CI, 0.50-1.65) mm narrower with the new machines than with the old machines. CONCLUSIONS: Technical improvements in modern ultrasound machines that have reduced the beam width affect fetal measurements in the lateral direction. This has clinical implications and new measurement charts are needed.
Authors: Katherine L Grantz; Sungduk Kim; William A Grobman; Roger Newman; John Owen; Daniel Skupski; Jagteshwar Grewal; Edward K Chien; Deborah A Wing; Ronald J Wapner; Angela C Ranzini; Michael P Nageotte; Stefanie N Hinkle; Sarah Pugh; Hanyun Li; Karin Fuchs; Mary Hediger; Germaine M Buck Louis; Paul S Albert Journal: Am J Obstet Gynecol Date: 2018-05-24 Impact factor: 8.661
Authors: Melissa M Amyx; Paul S Albert; Alaina M Bever; Stefanie N Hinkle; John Owen; William A Grobman; Roger B Newman; Edward K Chien; Robert E Gore-Langton; Germaine M Buck Louis; Katherine L Grantz Journal: Am J Obstet Gynecol Date: 2019-08-24 Impact factor: 8.661
Authors: Debra Paoletti; Lillian Smyth; Susan Westerway; Jon Hyett; Ritu Mogra; Stephen Haslett; Michael Peek Journal: Australas J Ultrasound Med Date: 2021-08-26
Authors: Katherine L Grantz; Jagteshwar Grewal; Paul S Albert; Ronald Wapner; Mary E D'Alton; Anthony Sciscione; William A Grobman; Deborah A Wing; John Owen; Roger B Newman; Edward K Chien; Robert E Gore-Langton; Sungduk Kim; Cuilin Zhang; Germaine M Buck Louis; Mary L Hediger Journal: Am J Obstet Gynecol Date: 2016-04-30 Impact factor: 8.661
Authors: Susan Campbell Westerway; Aris T Papageorghiou; Jane Hirst; Fabricio da Silva Costa; Jon Hyett; Susan P Walker Journal: Australas J Ultrasound Med Date: 2015-12-31